Screw-plate



Z. L. JACOB. SOREW PLATE.

No. 28,279. Patented May '15, 1860.

Elven/Z2 m: Nonms PCYERS 00.. mmaumu. wuummamp. a

UNITED STATES PATENT OFFICE.

ZALMON L. JACOBS, OF HEBRON, CONNECTICUT.

SCREW-PLATE.

Specification of Letters Patent No. 28,279, dated May 15, 1860.

To all whom it may concern:

Be it known that I, ZALMON L. JACOBS, of Hebron, in the county of Tolland, in the State of Connecticut, have invented a new and useful Improvement in Screw-Plates; and I do hereby declare that the following is a full, clear, and exact description of the construction and operation thereof, reference being had to the accompanying drawings, making a part of this specification, in which Figure l is a perspective View; Figs. 2 and 3 longitudinal sections; and Fig. 4 a transverse section.

Similar letters of reference indicate like parts in all the figures.

To enable others skilled in the art to which my invention appertains, to make and use the same, I will proceed to describe its construction and operation.

The screws A A Figs. 1, 2, 3, are fitted loosely into the hubs B B, of the body of the stock C, so that their axes being extended toward each other will meet and form one straight line passing through the center of the circular chamber D Figs. 2, 3, 4.

Within the chamber D, and between the screws A A, are arranged the dies E, E, having cutting edges formed in the usual manner, in pairs, at F F, G G, H H, I I, any desired pair of which edges may be made to face each other, and to be in a line with the axes of the screws A A, which is the position in which they are required for use. To prevent longitudinal movement of the dies, and yet, to permit those portions thereof required for use to occupy positions more or less remote from each other, as represented by the full and dotted lines of Fig. 3, the said dies E E, are pivoted to the body of the stock C, near those ends of the dies most remote from the portions required for use. For this purpose the holes J, K, L, M are made in the dies near their ends, and the pins or pivots N N N N, of a size to fit the said holes, are firmly fixed in the body of the stock C, and project a suitable distance into the chamber D. Of those pins two are arranged on the line 0 O, and two on the line P P, which lines are parallel to the axial line of the screws A A, and at such distances therefrom, that when the holes J K receive the pins on the line 0 O the cutting edges at F F will be in line with the axes of the screws, as represented by the full lines in Fig. 2; and when the holes L M receive the pins on line P P the edges at G G will occupy that position, as represented by the dotted lines of the same figure. The cutting edges on one side of each die alternate with those on the opposite side thereof, and all of them are so arranged, that when the position of the dies is reversed, as represented in Fig. 3, the edges at H H and I I will occupy the positions before occupied by those at F F and G G respectively. In order to prevent the movement of the dies in the direction of the axes of the pivots to which they are attached, the annular plate Q, Figs. 1 and L, is made use of; being attached to the body of the stock by means of a screw thread R, formed on its periphery, which fits into a screw formed on the inner periphery of the circular chamber D; and, to facilitate the turning of said plate, a rim or flange S is cast, or otherwise made, thereon. The dies are of an equal thickness and lie upon the plane surface of the bottom of the chamber D, and the said plate Q is screwed into the said chamber until it touches the dies and produces the effect for which it is intended. Such is the form and arrangement of the several parts of my device. The manner of using it may be briefly stated, as it differs in no important particular from that of using the screw plates in common use. The dies are arranged with any desired pair of their cutting parts facing each other and in line with the screws A A; the plate Q, is made to secure said dies in their places; and the screws A A are turned outward sufficiently to allow the dies to be opened so as to receive the bolt or rod to be operated upon. The said screws are then turned inward so as to press the edges of the dies into the bolt or rod-aforesaid, and the plate is made to revolve around the said bolt or rod, when the desired thread will be formed thereon.

Having completed the description of the construction and operation of my invention, it may be proper to point out some of its advantages. It will be observed that the forms of the body of the stock C and the plate Q are such, that they may be turned and finished throughout in a lathe, the pins being afterwards secured in their places. This feature enables me tastefully and accurately to fit and finish those parts at a small cost. The formof my dies, and the mode described of attaching them to the body of the stock, also possesses advantages in regard to c0st0f .constrnction a'swell as in the small quantity of stelthey contain in comparison with the number of their cut-' parts, in the facilitywith which their many cutting parts withinithe stock where they are least likely to be lost or mislaid. The alternate arrangement of :the cutting parts .of-the dies is preferred, forthedreason that the die, so made, isistrongerthan ifit were cut away at opposite points and *because the intermediate pieces are ,required osition for between the screws anddiesgas'woul'd otherwlse be necessaryto rotect the dies.

Having thus descri ed my invention what TI CIaim-and desire to secure by Letters Patent as an improved article of manufacture A screw plate provided with changeable pivoted dies E, screws A, stock C, pins N, .and plate-Q, substantially .as herein shown and described.

ZALMON L. JAGGB'S.

Witnesses:

ORRIN C. WHITE, WM. T. JONES. 

